A documentary/recruitment film originally intended for showings outside the United States to promote careers in public health and American methods in public health education. Directed by social documentarian Willard Van Dyke, and delivered entirely in the characteristic voice-over narration of that genre, the film centers around a young doctor, who during the course of his medical residency at the New York Presbyterian Hospital becomes disillusioned with the failures of the medical profession to address larger social and environmental health factors and discovers the field of public health. The young doctor moves to Baltimore to study at the Johns Hopkins School of Hygiene and Public Health and finds his professional calling fighting a diphtheria outbreak in the poverty-stricken streets and row-houses of East Baltimore.